1. Field of the Invention
The invention relates to an apparatus for receiving and issuing sheets. Such apparatuses are suitable for example for automatic service machines in which bank notes are received or issued.
2. Description of the Prior Art
An automatic machine for receiving or issuing larger amounts of money, which is suitable for the cash point business of banks, is known for example from United Kingdom patent application GB-A-2161145 and German patent application DE-A-3 519 635. Bank notes which are sorted on the basis of their nominal values are stacked in intermediate storage arrangements until they have to be issued to a customer. The stacks of bank notes are fed on their top side by means of the bank notes which are paid in by the customers, while in a note issuing operation the lowermost bank note of the predetermined stack of notes is pulled out by means of a friction wheel.
United Kingdom patent application GB 1542355 and German patent application DE-A-2 751 422 also disclose a singling or separating apparatus which involves the use of reduced pressure for lifting individual bank notes from the stack of notes. The one end of the uppermost note of the stack of notes is held fast under a retainer plate. The other end of the uppermost bank note is disposed directly beneath a suction roller with an axis arranged fixedly above the stack, which at a predetermined moment in time lifts the bank note by means of a reduced pressure; in that situation, by virtue of rotary movement of the suction roller through 180.degree., an individual bank note is pulled out beneath the retainer plate and passed to a transportation system.
In such apparatuses the mechanical loading applied to the bank notes is high, and that requires high values in respect of their mechanical strength. That value falls below an acceptable limit value in relation to heavily used bank notes so that such notes can give rise to mechanical faults and disturbances in the apparatus.
Swiss patent application No. 02 566/90-1, filed on Aug. 6, 1990, and its corresponding U.S. patent application entitled "Apparatus for Stacking Sheets" by Andre Gerlier, which is being filed on even date herewith (both of which are incorporated herein as if printed in full below), describe an apparatus for stacking sheets, in which a carriage which is displaceable over at least one stack changes the geometry of transportation belts by means of guide rollers in order to deposit the sheet on the stack without the transportation belts or the sheet to be deposited sliding on the previous top sheet of the stack. In that way it is possible for sheets falling in a wide range of values in terms of mechanical strength to be processed in a fault-free manner. Depending on time synchronisation of the supply of sheets to the apparatus and the movement of the carriage, the sheet can be deposited in a predetermined manner on one of a plurality of juxtaposed stacks over which the carriage passes.